4 Grades

Just before the end of the term four high school students were discussing their chances for certain grades. The following remarks contain the gist of their hopes and fears.

Jack: We'll all get different grades. If I get an A, then Lucy will get a D.
Jean: If Lucy gets a C, then Jack will get a D. Jack will get a better grade than Paul.
Lucy: If Jean doesn't get an A, then Jack will get a C. If I get a B, then Paul won't get a D.
Paul: If Lucy gets an A, then I'll get a B. if Jean doesn't get a B, I won't either.
When the final examinations were graded and the term marks made out each of the four passed, and strange as it may seem, each received a grade that checked exactly with all the ideas they had previously expressed.